Noun
English Wikipedia has an article on:cointegrationWikipedia
cointegration (countable and uncountable, plural cointegrations)
(mathematics) The condition of two non-stationary time series whose linear combination is stationary
A potentially useful property of forecasts based on cointegration is that when extended some way ahead, the forecasts of the two series will form a constant ratio, as is expected by some asymptotic economic theory. Clive Granger